Backup tool

ABSTRACT

A manually held tool to back up material through which riveting is undergoing and which counteracts the driving force from a rivet or fastener gun. The tool comprises an elongated hollow tubular shank supporting a nylon sleeve frictionally mounted in its bore and protruding slightly beyond the end of the shank. An enlarged handle member is integrally formed at the other end of the tubular shank, with the shank&#39;&#39;s bore extending therethrough. A pusher assembly is mounted within the handle in the bore for providing stability to the nylon sleeve, as against a riveting force, and to adjustably position the nylon sleeve. The pusher assembly is recessed at its leading end to prevent damage to the fastener when a minimum of nylon cushion protrudes from the shank.

Winter et al.

I 1 BACKUP TOOL [75] Inventors: Gordon Winter, Burbank; J. O.

Adcock, Sun Valley, both of Calif.

[73] Assignee: Lockheed Aircraft Corporation,

Burbank, Calif.

[22] Filed: Oct. 1, 1973 [21] Appl. No.: 402,183

[52] US. Cl. 72/465; 29/243.53; 29/275; 29/283; 72/479; 72/481 [51] Int.Cl. B2lj 15/38 [58] Field of Search 29/24353, 243.54, 271, 29/275, 283,280, 282; 72/464, 465, 466, 479, 481, 478, 482; 227/15, 140, 151, 154

[56] References Cited UNITED STATES PATENTS 1,450,414 4/1923 Ferguson72/482 1,838,973 12/1931 Wilder 227/15 2,244,047 6/1941 Butter.....227/154 2,353,559 7/1944 Hajek 72/479 2,581,659 1/1952 Hoffman 72/3542,666,201 l/l954 Van Ordenw. 227/140 2,786,203 3/1957 Trechiokas 227/1512,905,034 9/1959 Turner 29/275 [4 1 Aug. 12, 1975 FOREIGN PATENTS ORAPPLICATIONS 455,529 2/1928 Germany ..29/243.54 364,354 8/1906 France..72/482 Primary Examiner-C. W. Lanham Assistant Examiner-E. M. CombsAttorney, Agent, or FirmBilly G. Corber; Frank L. Zugelter; Lowell G.Turner [5 7] ABSTRACT A manually held tool to back up material throughwhich riveting is undergoing and which counteracts the driving forcefrom a rivet or fastener gun. The tool comprises an elongated hollowtubular shank supporting a nylon sleeve frictionally mounted in its boreand protruding slightly beyond the end of the shank. An enlarged handlemember is integrally formed at the other end of the tubular shank, withthe shanks bore extending therethrough. A pusher assembly is mountedwithin the handle in the bore for providing stability to the nylonsleeve, as against a riveting force, and to adjustably position thenylon sleeve. The pusher assembly is recessed at its leading end toprevent damage to the fastener when a minimum of nylon cushion protrudesfrom the shank.

9 Claims, 2 Drawing Figures T -A- fA/H'HH JH MJW,v.m. 33 20 I 1 BACKUPTOOL BACKGROUND OF THE INVENTION 1. Field of the Invention The field ofart to which the invention is most likely to pertain is located in aclass of devices generally relating to a rivet set, holder or tool.Class 72, Metal Deforming, US. Patent Office Classification, may be theapplicable general area of art in which the claimed subject matter ofthe type involved here may be classified.

2. The Prior Art Examples of prior art devices in the arts to which thisinvention most likely pertains are U.S. Pat. Nos. 378,341; 1,450,414;1,462,293; 2,105,391; 2,388,895; and 2,581,659.

3. Problems in the Prior Art Various types of rivets and other fastenersare used in increasing volume in industries demanding secured plate orother structural assemblies. They are shot in with (rivet) guns and thecomponents these articles fasten must be backed up effectively, duringassembly, without damage to part or structural surfaces. For thispurpose, special nylon-tipped back up bars were developed. Dozens, andperhaps hundreds, of these bars are often utilized by a single company.In use, these back up bars have become mutilated and worn (the nylonmaterial portions, i.e.) in relatively short time. Thus, reconditioningof these tools is a constant timeconsuming and costly effort.

In the past, the repair or reconditioning work generally compriseddrilling out and discarding the worn-tipnylon sleeve member, discgrinding and sanding the affected bar tool end, boring and finishing tolength a new tipped nylon sleeve, and re-assembling the complete bar.The average labor time required has been 0.5 hour per bar. Thus, anexcessive amount of out-of service use for back-up bars, in terms oftime and cost, has developed in order to recondition this type of toolfor re-utilization. Without such reconditioning, damage would continueto the rivet assemblies to which the back-up bar would be applied.

Furthermore, as evident from the above old procedure, a waste of nylonsleeve material had always resulted because of the fact that asubstantial amount of the nylon sleeve would remain within the confinesof the back-up tool. It would never be used, as it was always necessaryto drill out this remaining substantial nylon portion in thereconditioning process for the tool.

This invention eliminates such wastage, expense and excessivereconditioning time. The improved tool materially reduces the time andcost of reconditioning and provides local maintenance in the usingdepartment or tool crib, by obviating attendant handling, transportationand clerical work, for at least 90 percent of repairs. It has beenestimated that this type of tool in the prior art has been out ofservice at least percent of its use able life awaiting repairs. Suchnon-use is eliminated by this invention, while more frequent tip renewalwill keep the tool in better condition.

It should be noted here that this invention is directed to a tool whoseprimary purpose is to back up or support the material being securedtogether rather than directed to the fastener itself.

SUMMARY OF THE INVENTION This invention relates to back-up toolsutilized during riveting procedures, and particularly relates to thecounterpart or back-up tool or device for the material being riveted orfastened together.

An object of this invention is to provide an improved back-up tool whichsupports an assembly and protects a fastener end.

Another object of the invention is to support thin structure whilepreventing local deformation to the rivetable structural assembly whichis being driven with interference fasteners or the like.

Another object of this invention is to obviate a reconditioningprocedure for such a tool and which in the past required an excessiveout-of-service time.

Still another object of this invention is to maintain an optimumcondition for tools of this nature.

A further object of this invention is to provide an ease of modificationto existing tools to conform to the subject matter of this invention.

These and other objects and advantages will become apparent upon a fulland complete reading of the following description, the appended claimsthereto, and

the drawing comprising one sheet.

BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENTReferring now to the drawing in which reference characters thereincorrespond to like numerals following hereinafter, FIGS. 1 and 2illustrate a tool or device 10 which incorporates the invention. Thedevice or tool 10 is generally referred to as a back-up bar which ismanually held by an operator on one side of a rivetable structuralassembly or the like which is being secured together by means of a rivetor fastener applied by a gun being operated by a workman on the otherside of such assembly. It should become readily apparent that thegeneral purpose of this type of tool is to support the thin structure ofsuch plate assemblies, to prevent local deformations that wouldotherwise occur when driving, say, interference fasteners or the likewith a gun into such plate assemblies, and to protect the end of the pinor rivet which passes through such assemblies.

The tool 10 comprises an elongated rigid hollow member, stem or shank 12on the one end of which a handle 14 is mounted for suitable grasping byan operator. A bore 16 (FIG. 2) extends longitudinally throughout thetool 10, i.e., throughout the length of the shank 12 and handle 14. Anylon or resilient sleeve 18 is securely mounted in the shank 12 so asto provide a projecting tip portion 22 on the opposite end 20 of theshank 12. Such securement is preferably provided by means of africtional fit; that is, the nylon inserts lateral or diametricaldimension is greater than that of the bore 16. The nylon insert 18 ishollow as shown at 24 and includes a length which preferably extendssubstantially the length of the shank 12, as shown in FIG. 2.

A pusher assembly 26 is mounted in the bore 16, behind the hollow nyloninsert 18, for propelling or translating such insert to maintain thelatters tip projection. The assembly 26 comprises a rigid shaft member30, preferably steel, against which a threaded screw member 32 bears.The threaded periphery of the member 32 cooperates with correspondingthreads 33 incorporated substantially within the portion of the bore 16disposed within the handle 14. The shaft member 30 pref erably includesan axially-oriented cavity 34 sufficiently deep for purposes describedhereinafter.

The pusher assembly 26 is provided to adjustably position the hollownylon insert 18 so as to provide for a continuing protrusion of its tip22 beyond the end 20, and for the life or complete consumation of thematerial constituting the sleeve 18.

In operation, the back up bar or tool 10 is hand held in a similarmanner as a bucking bar for rivets. The projecting tip 22 of the insert18 is firmly held to one side of the plate assembly (not shown) aboutthe hole through which a rivet, fastener or the like is to be installedfrom the other side of such plate assembly. The handle 14 is grasped byan operator to firmly hold the device 10 in position. As the rivet orthe like comes through the hole, it inserts itself into or is caught bythe hollow insert 18 until such installation is completed. The tool 10is then removed with ease from its position about the plate assemblyhole and the rivet or fastener protruding therefrom.

Over a number of operations for the tool 10, the protruding tip 22slowly wears down, and thus must be replaced in order to provide acontinuous useful tip so as to prevent damage by the rigid member 12upon the rivet or its supporting plate assembly. The screw member 32 isrotated to propel or translate the shaft element 30 so as to force outor push a length portion of the hollow insert 18 beyond the end 20 ofthe shank 12. A trimming of the new projecting tip may be in order, anda slight readjustment of position of the insert 18 made. Suchpositioning or adjustment may be continued throughout the entire lengthof the nylon insert, even up to and past its last 5/ 16 inch remainingportion.

Preferably, the tool is made from steel and has its shank l2 neckeddown, from the dimensions of the handle 14, to a circular configuration.The handle 14 is hexagonally-configured in its cross-sectional area inorder to provide a supporting surface 40 when in nonuse. I.e., it may bereadily set upon a table without rolling. The shank 12 is preferablyslightly longer than the length of and in longitudinally alignment withthe handle 14 itself, the illustration of which is manifest in FIG. 2.The pusher assembly 26 should be of a length sufficient to push insert18 completely out of the end 20 of the shank 12. The axial relief orcavity 34 in the member 30 provides protection to a pin, rivet, orfastener or the like which is being driven through a pre-drilled hole inthe work area of the plate assembly or the like to which the device 10is applied. Such cavity 34 is sufficiently deep so as to take the lengthof such pin, etc., driven through the assembly. An important advantageby inclusion of this cavity 34 is that the fastener, which is beingdriven, will not bottom-out when the nylon tube insert 18 is almost usedup. Also, the shank 12 is preferably tubular or cylindrical as is thenylon insert 18.

It should now be evident that the body of the tool 10 is relativelyheavy to provide the inertia required to counteract the driving force ofthe rivet gun (i.e., preventing a bounce off of tool from plate). It ishexshaped to prevent it from rolling when laid down. Its tubular shanksupports the nylon sleeve and provides entrance into narrow places whereit has been necked down in size from that of the handle. The pusherassembly provides stability and absorbs the rotation of the crew memberas the nylon sleeve is advanced. The shaft 30 is recessed at its leadingend to insure that even with a minimum of nylon cushion, the rivet orfastener will not be damaged.

Also, it should be apparent that the tool 10 is readily adaptable to(automatic) machine operation.

The assembly of the tool 10 should be evident from the abovedescription; however, briefly in summary, the insert 18 is frictionallyforced into the bore 16, the shaft 30 slid into the bore 16 to behindthe insert 18, and the screw member 32 threaded to threads 33 to retainthe shaft 30 and to act as the means to push and adjust the length ofthe insert 18 past the end of the bore 16.

The advantage of reduced time and costs becomes very apparent when thetime to adjust an insert member 18 in the bore 16 (minutes), multipliedby the 12- 16 sections of a given length of insert member which can beused before introducing a new insert, is compared to the 0.5 hour it hastaken in regard to reconditioning the old tool.

Pursuant to the requirements of the patent statutes, the principle ofthis invention has been explained and exemplified in a manner so that itcan be readily practiced by those skilled in the art to which itpertains, or with which it is most nearly connected, suchexemplification including what is presently considered to represent thebest embodiment of the invention. However, it should be clearlyunderstood that the above description and illustrations are not intendedto unduly limit the scope of the appended claims, but that therefrom theinvention may be practiced otherwise than as specifically described andexemplified herein, by those skilled in the art, and having the benefitof this disclosure.

Therefore, what we claim as patentably novel is:

1. A tool comprising an elongated rigid body member having ends and anaxial bore extending therethrough,

a tubular resilient insert mounted in said bore and being slidablysecured by press fitting within said bore and having an end portionprotruding from said one of said ends, and

means mounted in said bore opposite said tubular insert for adjustablyfixing the position of said insert relative to said one of said ends.

2. The tool of claim 1 wherein said positioning means comprises a pusherassembly.

3. The tool of claim 2 wherein said pusher assembly comprises a barmember of substantially the same diameter as said tubular insert andhaving an axiallyoriented relief, and means for propelling said barmember.

4. The tool of claim 3 wherein said propelling means comprises a screwmember mounted in said bore being threaded for cooperation with saidscrew member to the extent required to propel said hollow insert pastsaid one of said ends, access to said propelling means being through theother of said ends.

5. A tool comprising an elongated rigid body member having opposite endsand having a longitudinal bore of substantially constant diameterextending between said ends,

a hollow insert mounted in said bore, being frictionally secured to saidbody member, and having an end portion protruding from one of saidopposite ends,

a pusher assembly having a bar member with an axially-oriented reliefadjacent said hollow insert, and means for propelling said pusherassembly against said insert, said bar member and said propelling meansmounted in said bore in tandem coaxial relation with and for adjustablypositioning said insert relative to said one of said opposite ends infixed relation.

6. The tool of claim 5 wherein said propelling means comprises a screwmember mounted in said bore, said bore being threaded for cooperationwith said screw member to the extent required to propel said insert pastsaid one of said opposite ends.

7. A tool comprising a shank having an end,

an enlarged handle mounted on said shank,

a longitudinal bore extending through said shank and handle,

a tubular flexible insert mounted in said bore for movement only inresponse to the application of force thereto and having an end portionprojecting from said shanks end,

a pusher assembly mounted in said bore and including a bar member and apropelling means in tandem coaxial relation with and for adjustablyfixing the position of said insert relative to said shanks end.

8. The tool of claim 7 wherein said pusher assembly includes a relief insaid bar member for acceptance of a fastener or the like.

9. The tool of claim 7 wherein said hollow insert is of a dimensiongreater than that of said bore thereby providing such securement,

1. A tool comprising an elongated rigid body member having ends and anaxial bore extending therethrough, a tubular resilient insert mounted insaid bore and being slidably secured by press fitting within said boreand having an end portion protruding from said one of said ends, andmeans mounted in said bore opposite said tubular insert for adjustablyfixing the position of said insert relative to said one of said ends. 2.The tool of claim 1 wherein said positioning means comprises a pusherassembly.
 3. The tool of claim 2 wherein said pusher assembly comprisesa bar member of substantially the same diameter as said tubular insertand having an axially-oriented relief, and means for propelling said barmember.
 4. The tool of claim 3 wherein said propelling means comprises ascrew member mounted in said bore being threaded for cooperation withsaid screw member to the extent required to propel said hollow insertpast said one of said ends, access to said propelling means beingthrough the other of said ends.
 5. A tool comprising an elongated rigidbody member having opposite ends and having a longitudinal bore ofsubstantially constant diameter extending between said ends, a hollowinsert mounted in said bore, being frictionally secured to said bodymember, and having an end portion protruding from one of said oppositeends, a pusher assembly having a bar member with an axially-orientedrelief adjacent said hollow insert, and means for propelling said pusherassembly against said insert, said bar member and said propelling meansmounted in said bore in tandem coaxial relation with and for adjustablypositioning said insert relative to said one of said opposite ends infixed relation.
 6. The tool of claim 5 wherein said propelling meanscomprises a screw member mounted in said bore, said bore being threadedfor cooperation with said screw member to the extent required to propelsaid insert past said one of said opposite ends.
 7. A tool comprising ashank having an end, an enlarged handle mounted on said shank, alongitudinal bore extending through said shank and handle, a tubularflexible insert mounted in said bore for movement only in response tothe application of force thereto and having an end portion proJectingfrom said shank''s end, a pusher assembly mounted in said bore andincluding a bar member and a propelling means in tandem coaxial relationwith and for adjustably fixing the position of said insert relative tosaid shank''s end.
 8. The tool of claim 7 wherein said pusher assemblyincludes a relief in said bar member for acceptance of a fastener or thelike.
 9. The tool of claim 7 wherein said hollow insert is of adimension greater than that of said bore thereby providing suchsecurement.